Week9 - SuperCollider - Physical Modeling

The Karplus-Strong (KS) Method for physical modeling is noise - filter - delay. After I recreated some of the example patches of this method, I thought about the task of how to modify the patch. I managed to create some unique sounds but no new instrumental sounds.

There are a number of parts and parameters of the KS patch that can be altered, but the effect is often minimal and slight. It was mentioned that this method could create some percussive sound as well as the plucked string sound. I was never able to create a percussive sound. Anyway, these are some things that can be altered within the original patch:

• Decay Time
• Pitch
• Envelope Attack
• Noise
• Delay

In the KS method, I am still confused as to exactly what the filter and delay are. In the examples the CombL.ar is used. This is a delay object, but is this the delay or the filter that this method is dependent on? or is it both the delay and the filter? However, this is the part of my patch that I feel has the most significant impact on the sound. Increasing the attack on the envelope also has a significant effect on the sound.

The following patch substitutes the CombL for a Ringz filter, thus making the pitch redundant.

//PHYSICAL MODELLING Ringz
(
    //Noise > Filter > Delay
    SynthDef(
    \noiseBurst,
   
    {   
    //Variables
    var    burstEnv,
        att            =    0,
        dec            =    0.001,
        delayTime,
        decayTime    =    10,
        midiPitch    =    69,        // A    = 440   
        noise,
        del;
       
    //Delay Time
    delayTime    =    midiPitch.midicps.reciprocal;   
       
    //Envelope
    burstEnv    =    EnvGen.kr(
                    envelope:    Env.perc(att, dec));
                   
    //Noise
    noise    =    PinkNoise.ar(burstEnv);
   
    //Delay
    del        =    Ringz.ar(
                    in:                noise,
                    freq:            delayTime,
                    decaytime:        decayTime,
                    add:            noise);
   
    //Output
    Out.ar(0, [del, del]);
    }
    ).play                   
)